A photographic light-sensitive material generally comprises a support made of various materials (e.g., cellulose triacetate, polyethylene terephthalate, an ordinary paper, and a paper coated with polyethylene terephthalate on both surfaces) and a silver halide emulsion layer provided on one side of the support directly or both sides of the sup port via an undercoating (or subbing) layer. If desired, the photographic material may be optionally provided with additional layers such as an intermediate layer a protective layer, a filter layer, an antistatic layer and an anti-halation layer. These additional layers generally contains a hydrophilic binder (e.g., gelatin) as their main component. An X-ray film, that is one example of photographic light-sensitive materials has photographic emulsion layer on both sides of the support, but most of the photographic light-sensitive materials are provided with a photographic emulsion layer on one side of the support. In the latter case, the photographic light-sensitive material has a free surface on the support where a photographic emulsion layer is not provided, and this free surface is generally called "a back surface" of the photographic light-sensitive material in this art. On the back surface of the photographic light-sensitive material is generally provided an auxiliary layer such as an anti-halation layer, an antistatic layer, an anti-curling layer or an overcoat layer to enhance photographic or physical qualities.
The photographic light-sensitive material having the above constitute is generally brought into contact with various apparatus in its process for the preparation including coating procedure, drying procedure, etc. or brought into contact with other various devices, machines or cameras in handling (for example, transferring procedure and winding or rewinding procedure in various stages such as picture-taking, developing, printing and projecting stages). When the photographic material is in contact with those apparatus or machines, seriously adverse effects are apt to be given to the photographic material. In addition, the same adverse effects are also given to the photographic material when dusts or waste fibers are attached to the material. For example, scratches or abrasions are brought about on the photographic emulsion layer side or the back surface side of the photographic material, or the photoraphic material does not run smoothly in a camera or other machines. Moreover, waste films (waste photographic materials) are produced. Particularly, scratches easily occur on the back surface of the photographic material, because this surface is frequently brought into contact with various devices. These scratches appear on a visible image during the printing stage or the projecting stage, resulting in serious problem in the practical use. Recently, the photographic light-sensitive material is treated under more severe conditions than the conventional ones, because the use thereof or the process for the preparation thereof is extended (for example, high-speed coating, rapid photographing or rapid processing is developed) or the photographic material is used in various circumstances such as in an atmosphere of high temperature and high humidity. Under such severe conditions, the photographic material is more easily scratched, or smooth running of the material in various machines is hardly obtained Accordingly, the photographic light sensitive material is desired to have high qualities of its surface even under such severe conditions.
For improving the slip properties and the resistance to damage on the surface of the photographic light-sensitive material, a lubricant (i.e., slip property-increasing agent) is conventionally contained in the surface layer of the photographic material. Examples of the lubricants generally employed for that purpose include polyorganosiloxane as described in Japanese Patent Publication No. 53(1978) 292, higher aliphatic acid amides as described in U.S. Pat. No. 4,275,146, higher aliphatic acid esters as described in U.K. Patent No. 927,446 and Japanese Patent Provisional Publications No. 55(1980).126238 and No. 58(1983) 90633, aliphatic acid diesters as described in Japanese Patent Publication No. 58(1983) 33541 and U.K. Patent No. 1,320,564, and higher aliphatic acid metal salts as described in U.S. Pat. No. 3,933,516.
Under the severe conditions as in the recent high-speed transferring stage, however, satisfactory effect can be hardly obtained by the above mentioned conventional method, although the slip properties and the resistance to damage of the photographic material can be improved to a certain level. Further, other problems still resides in the conventional method. For example, when silicone is employed as a lubricant of a backing layer (i.e., a layer provided on the back surface) the added silicone moves to the surface of the support where a photographic emulsion is to be coated to give an adverse effect in the emulsion-coating procedure, that is, cissing or watting takes place to markedly deteriorate the coating properties of the sur face. The surface layer containing above the lubricant shows relatively high slip properties and high resistance to damage immediately after the formation of the surface layer, but the layer deteriorates in those properties with time (that is, the lubricant diffuses within the surface layer), or white powders are produced on the back surface because of bleeding of the lubricant. Further, the lubricant is melted out or diffuses off from the surface layer during the development stage, whereby favorable effect cannot be given even by adding the lubricant Furthermore, thus diffused lubricant sometimes pollutes the treating liquid.
For provision of a backing layer using the lubricant there can be generally used a process comprising the steps of dissolving or dispersing the lubricant singly or with a binder in an appropriate solvent to prepare a coating solution (or dispersion), and coating the solution or the dispersion over a support. If the lubricant has a nature of swelling the support, the lubricant easily diffuses within the support and hardly remains on the surface of the sup port. As a result, satisfactory slip properties cannot be obtained. For enhancing the slip properties, the lubricant is generally used in a larger amount in the conventional method, but in this case, the lubricant is easily deposited on the surface of the photographic material owing to the increased concentration of the coating solution, and thereby the stages for the preparation of the photographic material polluted.